Portable devices, such as mobile phones, tablet devices, digital cameras, wearable devices, and other types of computing and electronic devices can be used in a variety of ways. Further, users can provide input in a variety of ways, such as by pressing a button, swiping a touch screen, giving a voice command, and so on. Conventionally, these portable devices required the user to press a button to turn on or wake up the device prior to enabling the user to execute an application or otherwise operate the device. For example, when a user's phone receives an incoming call, the user is generally required to press a button or swipe the touch screen to answer the call. In some instances, the user may have difficulty answering the phone, such as when attempting to swipe the touch screen with a wet finger or failing to properly press the button such that the device fails to connect the call. Further, conventional portable devices can be difficult to operate with the same hand that is holding the device, which many users attempt to do while they are multi-tasking. These difficulties can lead to missed calls or a poor user experience, resulting in user frustration.
In addition, gestures are becoming more common among portable devices as a way for users to provide input. For example, some touch-screen devices can recognize different swipe directions as corresponding to different commands. Generally, however, touch-screen devices require that the touch screen be powered on to enable the device to recognize the gesture.